Temporal and Geospatial DBMS. CSCE 4523 Sean Young

Transcription

1 Temporal and Geospatial DBMS CSCE 4523 Sean Young

2 Outline Temporal Relational vs Temporal Valid/Transaction Time Temporal SQL Geospatial Spatial Data Types Demo Spatio-Temporal Examples

3 Temporal DBMS A database system that provides special support for handling data with a temporal component, namely time. (Patel & Phillips, 2003)

4 Video

5 Relational vs Temporal Rows of individual columns Adds a third dimension, time Snapshot of the data in time Only shows current state, or if attempting to show the past, gets very cluttered and hard to manage Allows us to see the data as it was at a particular point in time Allows querying based on time, eliminating noise and unwanted data

6 Representing Time Valid Time When the fact was true with respect to the real world Historical Database Transaction Time When the fact was "true" according to the database Rollback Database Bitemporal Database Stores both valid and transaction time

7 Example from Wikipedia - John Doe There is a database table named Person with two fields: name and address. For this example we'll look at a man named John Doe

8 Example from Wikipedia - Standard Database Date What Happened in the Real World Database Action What the Database Shows April 3, 1975 John is born Nothing No person known as John Doe April 4, 1975 John's father officially reports John's birth Inserted: Person(John Doe, Smallville) Lives in Smallville Aug 26, 1994 John moves to Bigtown, but forgets to register his new address Nothing Lives in Smallville Dec 27, 1994 John registers his new address Updated: Person(John Doe, Bigtown) Lives in Bigtown Jun 1, Sept 3, 2000 John moved to Beachy. Never reported it (to avoid residence tax) Nothing Lives in Bigtown April 1, 2001 John dies Deleted: Person(John Doe) No person known as John Doe

9 Example from Wikipedia - Valid Time Person table gets two new fields: ValidFrom, ValidTo Person(John Doe, Smallville, 3-Apr-1975, inf) Person(John Doe, Bigtown, 26-Aug-1993, inf) Person(John Doe, Smallville, 3-Apr-1975, 26-Aug-1993) Person(John Doe, Bigtown, 26-Aug-1993, 1-Apr-2001) Auditor discovers on Feb 2, 2001 that John lived in Beachy: Person(John Doe, Bigtown, 26-Aug-1993, 1-Jun-1995) Person(John Doe, Beachy, 1-Jun-1995, 2-Sep-2000) Person(John Doe, Bigtown, 3-Sep-2000, 1-Apr-2001)

10 Example from Wikipedia - Transaction Time Person table gets two new fields: TransactionFrom, TransactionTo Person(John Doe, Smallville, 3-Apr-1975, inf, 4-Apr-1975, 27-Dec-1994) Person(John Doe, Smallville, 3-Apr-1975, 26-Aug-1993, 27-Dec-1994, inf) Person(John Doe, Bigtown, 26-Aug-1993, inf, 27-Dec-1994, 2-Feb-2001) Person(John Doe, Bigtown, 26-Aug-1993, 1-Jun-1995, 2-Feb-2001, inf) Person(John Doe, Beachy, 1-Jun-1995, 2-Sep-2000, 2-Feb-2001, inf) Person(John Doe, Bigtown, 3-Sep-2000, inf, 2-Feb-2001, 1-Apr-2001) Person(John Doe, Bigtown, 3-Sep-2000, 1-Apr-2001, 1-Apr-2001, inf)

11 Temporal SQL When time is attached to a primary key, you can use the key over and over, and other tables linked to that key may not be time-aware Deletes have different meanings if you store valid time Richard Snodgrass proposed a temporal extension to SQL in Work began on TSQL with the intent to combine it into the SQL standard, but the project was cancelled in 2001 due to lack of progress. TSQL, although not part of the standard, remains useful in various temporal DBMS and temporal extensions to RDBMS. Some parts, namely the ability to create "application-time period tables" (valid time) and "system-versioned tables" (transaction time) have been worked into SQL:2011 Part 2: SQL/Foundation

12 Geospatial DBMS Storing spatial information in a database

13 Video

14 Geospatial DBMS and GIS Combines nonspatial tabular data with locational information in an extension of traditional RDBMS (usually) Spatial information requires special data types: Points Lines Polygons Others (Polylines, Multipart Polygons, Volumes, etc.) Spatial information allows for location-based queries and spatial statistics Generally dealt with in a Geographic Information System (GIS) Most popular and powerful GIS software in the US is the ArcGIS suite created by Esri

15 Demo Esri's ArcGIS Software

16 Vector Overlay Forested Wetland

17 Erase - SQL NOT Logic Forested NOT Wetland

18 Erase - SQL NOT Logic Wetland NOT Forested

19 Union - SQL OR Logic Wetland OR Forested

20 Intersect - SQL AND Logic Wetland AND Forested

21 Symmetrical Difference - SQL XOR Logic Wetland XOR Forested

22 Spatio-Temporal DBMS Manages both space and time

23 Spatio-Temporal Database Extends the spatial database to include time Allows tracking of changing geometries or spatial locations By tracking both location and time, we can record movement Historical Real-time Future

24 Example: Arkansas County Formation

25 Example: Japan Earthquake Trends

26 Summary Temporal DBMS Stores Valid Time, Transaction Time, or Both Tracks changes without "forgetting" past facts Geospatial DBMS Stores locational information in special data types Allows for spatial queries and statistics Spatio-Temporal DBMS The best of both worlds, including storing movement and predicting trajectories, etc.

27 References Patel, J. & Phillips, I. (2003). Temporal database systems. MEng, Individual Project, 18. Retrieved from teaching/student_projects/jaymin_patel.pdf Sivalingham, Ponmalar, Amin, Moraali, Daniel & Sunny. (n.d.). Temporal Database PPT Presentation. PowerShow.com. Retrieved Oct 1, 2012, from Rashid, A.N.M.B., & Hossain, M.A. (2012). Challenging Issues of Spatio-Temporal Data Mining. Computer Engineering and Intelligent Systems, 3(4), TimeConsult. (2005, May 21). About temporal data. TimeConsult. Retrieved Oct 2, 2012, from TemporalData/TemporalData.html JCC Consulting, Inc. (2012, July 1). JCC's SQL Standards Page. JCC Consulting, Inc. Retrieved Oct 1, 2012, from sql.htm Temporal database. (2012, Oct 2). Wikipedia. Retrieved from Snodgrass, R.T. (Ed.). (1995). Part IV: Language Specification. The TSQL 2 Temporal Query Language (p. 674). Kluwer Academic Publishers. Arkansas County Formation Map. (2012). Webmap, GenealogyInc.com. Retrieved from Countries, 200 Years, 4 Minutes - gapminder.org. (n.d.). Retrieved Oct 3, 2012, from Geospatial Revolution Project A Public Media Project. (n.d.). Retrieved Oct 3, 2012, from